益生菌发酵对荔枝浆理化特性和挥发性成分的影响研究

Effects of probiotics fermentation on the physicochemical properties and volatile components of Litchi pulp

以荔枝浆为对象,考察益生菌发酵对荔枝的理化特性和挥发性成分的影响。结果表明:采用植物乳杆菌和乳酸芽孢杆菌DU-106进行复合发酵,pH与还原糖含量随着发酵时间的增长而下降,总酸与乳酸含量随着发酵时间增长而上升,乳酸含量从发酵前的1.19 mg/g上升至9.13 mg/g。另外,采用GC-MS对比益生菌发酵前后挥发性成分差异,结果表明在发酵前共测得荔枝中含有52种挥发性成分,包括石竹烯、柠檬烯、芳樟醇等荔枝主要风味成分,其含量与发酵时间呈正相关,而榄香烯、杜松稀等成分则相对发酵前含量有所下降。荔枝风味成分以烯类物质和醇类物质为主,发酵后除醛类物质含量种类下降外,其余物质含量与种类数量均增加,风味物质更加多元化,为发酵荔枝的相关产品开发提供理论依据。

Taking lychee pulp as the object,the effect of probiotic fermentation on the physical and chemical properties and volatile components of lychee pulp was investigated.The results showed that:using Lactobacillus plantarum and Bacillus lactis DU-106 for compound fermentation,the pH value and reducing sugar content decreased with the fermentation time,the total acid and lactic acid content increased with the fermentation time.The lactic acid content increased from 1.19 mg/g to 9.13 mg/g.In addition,GC-MS was used to compare the differences of volatile components of probiotics before and after fermentation.The results showed that before fermentation,52 kinds of volatile components were detected in Litchi,including caryophyllene,limonene,linalool and other main flavor components of Litchi.Their contents were positively correlated with the fermentation time,while the content of elemene,juniper and other components decreased than their contents before fermentation.The flavor components of lychee were mainly olefins and alcohols.After fermentation,except for the decrease of aldehyde content,the content and quality of other substances increased,and the flavor substances were more diversified,which provides a theoretical basis for the development of related products of fermented lychee.